JP2016071249A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus that can reduce a noise from the apparatus.SOLUTION: An optical writing device 21 such as optical writing means is covered by a support plate 90 supporting the optical writing device 21 and a duct 111. The support plate 90 has an opening 99 formed at a position opposite to a scanner attachment part 182 such as an attachment part of an optical housing 80 such as a housing when the optical writing device 21 is attached to an apparatus body, so as to release, from the opening 99, a noise generated from the scanner attachment part 182 and bearing part 50a during drive of a polygon scanner 50 such as deflection means.SELECTED DRAWING: Figure 10

Description

  The present invention relates to an image forming apparatus such as a printer, a facsimile machine, and a copying machine.

  2. Description of the Related Art Conventionally, there has been known an image forming apparatus including an optical writing device that writes a latent image by irradiating a photosensitive member as a latent image carrier with a light beam emitted from a light source. The optical writing unit includes a plurality of optical components such as a light source, a polygon scanner as a deflecting unit, a pre-polygon optical system installed in a light path from the light source to the polygon scanner, a scanning lens, and a folding mirror. The polygon scanner and the optical component are housed in a housing.

Patent Document 1 describes an image forming apparatus provided with a duct covering the casing. Specifically, a plurality of legs are provided on the bottom surface of the housing, such as a mounting portion to which the polygon scanner and optical components are attached, so as to protrude from the bottom surface of the housing. Supported by a support plate. As a result, the support plate faces the bottom surface of the housing with a predetermined gap. The duct is attached to the support plate so as to cover the housing. The duct extends toward an exhaust port provided on the side opposite to the support plate with the housing interposed therebetween, and is connected to an exhaust fan serving as an airflow generating unit provided facing the exhaust port.
The air in the duct flows along the upper and side surfaces of the casing by the exhaust fan, and the air also flows between the support plate and the bottom surface of the casing, thereby cooling the optical writing device. The air after cooling the optical writing device flows in the duct toward the exhaust port, and is exhausted from the exhaust port to the outside of the apparatus.

  Patent Document 1 describes that by covering the casing with a duct, the air flow flowing in the duct comes into contact with almost the entire outer peripheral surface of the casing, and the cooling efficiency of the optical writing device is improved. In addition, it is described that when the casing is covered with a duct, the sound when the polygon scanner is driven is shielded by the duct, and noise leaking outside the apparatus is reduced.

  In addition to the wind noise generated when the polygon mirror of the polygon scanner rotates at high speed, there are also sounds generated from the bottom of the housing that is the mounting surface where the polygon scanner is mounted. . The sound generated when the polygon scanner is driven from the bottom of the housing is generated by the following mechanism. That is, when the polygon mirror rotates at high speed, the polygon scanner vibrates, and the vibration propagates to the bottom surface of the housing, which is the mounting portion to which the polygon scanner is mounted, and the bottom surface of the housing vibrates. As the bottom surface of the housing vibrates, the bottom surface of the housing acts like a speaker and generates sound.

  The sound emitted from the bottom surface of the housing is reflected by the respective surfaces of the support plate and the bottom surface of the housing, and proceeds through the gap between the support plate and the bottom surface, and is finally reflected by the support plate. After that, there is a possibility that the inside of the duct moves toward an exhaust port provided on the side opposite to the support plate with the casing interposed therebetween and leaks from the exhaust port.

  The present invention has been made in view of the above problems, and an object thereof is to provide an image forming apparatus capable of reducing the noise of the apparatus as compared with Patent Document 1.

  In order to achieve the above object, a first aspect of the present invention includes a latent image carrier, a light source that irradiates light, deflection means that deflects and scans the light emitted from the light source, and the deflection means. An optical writing unit having a housing and irradiating the latent image carrier with a light beam deflected and scanned by the deflecting unit to write the latent image on the latent image carrier; and the deflecting unit of the housing Is provided on the side opposite to the side on which the support plate is disposed across the optical writing means, and a support plate that supports the housing and is opposed to the outer peripheral surface of the mounting portion to which the optical writing unit is mounted. And a duct for covering the casing from the side opposite to the side where the support plate is disposed, a duct for flowing air around the casing toward the exhaust outlet, and the casing After the air around the body flows along the outer peripheral surface of the casing, it flows to the exhaust port. An image forming apparatus comprising an airflow generating means for generating a flow, at a location to face the outer peripheral surface of the mounting portion of the support plate, it is characterized in that an opening is provided.

  According to the present invention, the noise of the apparatus can be reduced as compared with the image forming apparatus described in Patent Document 1.

1 is a diagram illustrating an outline of an image forming apparatus. (A) is a perspective view of a process cartridge, (b) is sectional drawing of a process cartridge. 1 is a schematic configuration diagram of an optical writing device. A perspective view of the optical writing device viewed from below. The top view which shows a support plate. The expansion perspective view near the 2nd positioning surface. The perspective view which shows the state by which the optical writing device was positioned and fixed to the support plate. FIG. 3 is a cross-sectional perspective view around the optical writing device. FIG. 3 is an enlarged cross-sectional perspective view around the polygon scanner of the optical writing device. The figure explaining the air flow around an optical writing device, and the propagation of sound at the time of driving of a polygon scanner. The figure which shows the modification of a muffling part. FIG. 6 is a view showing a modification in which the lower surface of the process cartridge is used as a wall that shields the waste toner bottle storage unit.

FIG. 1 is a diagram showing an outline of an image forming apparatus according to an embodiment of the present invention.
An image reading apparatus 200 is attached to the upper part of the apparatus main body 100 of the copying machine as an image forming apparatus.

A process cartridge 1 is provided inside the apparatus main body 100.
FIG. 2A is a perspective view of the process cartridge, and FIG. 2B is a cross-sectional view of the process cartridge.
As shown in FIG. 2B, the process cartridge 1 includes a photosensitive member 10 that is a latent image carrier, a charging device 11 that is disposed around the photosensitive member 10 and that acts on the photosensitive member 10, and a developing device. 12 and a cleaning device 14. The process cartridge 1 is detachably attached to the apparatus main body 100. Since the photosensitive member 10, the charging device 11, the developing device 12, and the cleaning device 14 are unitized as the process cartridge 1, replacement and maintenance work is facilitated. Further, it is possible to maintain the positional accuracy between the members with high accuracy, and to improve the quality of the formed image.

  The charging device 11 serving as a charging unit applies a charging bias to apply a charge to the surface of the photoconductor 10 to uniformly charge the photoconductor 10, and an adhering material such as toner attached to the surface of the charging roller 11a. And a removing roller 11b to be removed.

  The developing device 12 as developing means has a first agent storage chamber V1 in which a first conveying screw 12b as developer conveying means is disposed. Further, it also has a second agent storage chamber V2 in which a second conveying screw 12c as a developer conveying means, a developing roller 12a as a developer carrying member, a doctor blade 12d as a developer regulating member, and the like are disposed. .

  In these two agent storage chambers V1 and V2, a developer which is a two-component developer including a magnetic carrier and a negatively chargeable toner is included. The first transport screw 12b is rotationally driven by a driving unit (not shown) to transport the developer in the first agent storage chamber V1 to the front side in the drawing. Then, the developer transported to the front side end portion of the first agent storage chamber V1 in the drawing by the first transport screw 12b enters the second agent storage chamber V2.

  The second transport screw 12c in the second agent storage chamber V2 is rotationally driven by a driving unit (not shown) to transport the developer to the back side in the drawing. In this manner, the developing roller 12a is disposed in a posture parallel to the second conveying screw 12c above the second conveying screw 12c that conveys the developer. The developing roller 12a includes a magnet roller fixedly disposed in a developing sleeve made of a non-magnetic sleeve that is rotationally driven.

  Part of the developer conveyed by the second conveying screw 12c is pumped up to the surface of the developing roller 12a by the magnetic force generated by a magnet roller (not shown) in the developing roller 12a. Then, after the layer thickness is regulated by a doctor blade 12d arranged so as to maintain a predetermined gap from the surface of the developing roller 12a, the layer thickness is regulated and conveyed to a developing region facing the photoconductor 10, and on the photoconductor 10 Toner is attached to the electrostatic latent image. By this adhesion, a toner image is formed on the photoreceptor 10. The developer that has consumed toner by development is returned to the second conveying screw 12c as the surface of the developing roller 12a moves. Then, the developer transported to the end of the second agent storage chamber V2 by the second transport screw 12c returns to the first agent storage chamber V1. In this way, the developer is circulated and conveyed in the developing device.

  Further, the developing device 12 includes a toner concentration sensor that detects the toner concentration of the developer in the first agent storage chamber V1. The toner concentration sensor measures the toner concentration of the developer from the magnetic permeability of the developer. When the toner concentration is low, the magnetic carrier is concentrated, so that the magnetic permeability is increased. When the value measured by the toner density sensor 124 exceeds the target value (threshold value), toner is supplied from the toner bottle 20 shown in FIG. 1, and the toner density is controlled to a constant density. The target value is determined based on the detection result obtained by detecting the toner adhesion amount of the toner pattern formed on the photoconductor 10 with an optical sensor (not shown).

  By such an operation, control is performed so that the reference pattern density on the photosensitive member is kept constant. However, when the toner in the toner bottle 20 runs out, the density reduction cannot be suppressed. In such a situation, the detection result of the toner pattern by the optical sensor is not improved despite the operation of supplying the toner from the toner bottle 20 for a predetermined period. Therefore, if the detection result of the toner pattern by the optical sensor is not improved despite the operation of replenishing the toner from the toner bottle 20, it is determined by means (not shown) that the toner has run out (toner end). (Or presumptive judgment).

  In addition, after the toner end is determined, the toner bottle 20 is replaced, and when the toner end recovery for supplying the toner in the replaced toner bottle 20 to the developing device 12 is performed, the following operation is performed. That is, the developing roller 12a and the conveying screws 12b and 12c are rotated in order to satisfactorily mix the replenished toner and the developer. At this time, in order to prevent the developer on the developing roller 12a from sliding unevenly, the photosensitive member 10 is also driven to rotate.

  The cleaning device 14 serving as a cleaning unit includes a cleaning blade 14 a that contacts the surface of the photoconductor 10 and scrapes off transfer residual toner attached to the photoconductor 10. In addition, a toner collection coil 14b is provided that conveys the collected toner collected in the collection unit W and collected by the cleaning blade 14a. The collected toner transported by the toner recovery coil 14b is transported to the developing device 12 or the waste toner bottle 35 by a toner transport device (not shown).

  A transfer device 17 as a transfer unit shown in FIG. 1 includes a transfer roller 16, and the transfer roller 16 is pressed against and brought into contact with the peripheral surface of the photoconductor 10. Further, a thermal fixing device 24 as a fixing unit is provided above the transfer device 17. The thermal fixing device 24 includes a heating roller 25 and a pressure roller 26. In addition, the apparatus main body 100 is provided with an optical writing device 21 as optical writing means. Further, the apparatus main body is provided with a plurality of sheet cassettes 22 for storing sheets S such as transfer paper and OHP film.

  The optical writing device 21 is supported by a support plate 90 provided so as to partition the waste toner bottle 35 and the optical writing device 21. In addition, a duct 111 is provided so as to cover the optical writing device 21, and the duct 111 is connected to an exhaust fan 112 disposed to face the exhaust port 113.

  When copying using the apparatus configured as described above, the user presses a start switch (not shown). Then, first, the contents of the original set on the image reading apparatus 200 are read. At the same time, the photoconductor 10 is rotated by a photoconductor drive motor (not shown), and the surface of the photoconductor 10 is uniformly charged by the charging device 11 using the charging roller 11a. Next, a writing process is executed using the optical writing device 21 by irradiating a light beam according to the content of the original read by the image reading device 200. Then, after forming an electrostatic latent image on the surface of the photoconductor 10, toner is attached using the developing device 12 to visualize (develop) the electrostatic latent image.

  At the same time as the user presses the start switch, the selected sheet S is sent out by the calling roller 27 from the multistage sheet cassette 22. Next, the sheet is separated one by one by the supply roller 28 and the separation roller 29 and sent to the supply path R1. The sheet S sent to the supply path R <b> 1 is conveyed by the sheet conveyance roller 30 and is abutted against the registration roller 23 and stopped. The transfer roller 16 is sent to a transfer nip formed in contact with the photoconductor 10 in accordance with the rotation timing of the toner image that is visualized on the photoconductor 10.

  The toner image on the photoreceptor 10 is transferred to the sheet S fed to the transfer nip by the transfer device 17. The residual toner on the photoconductor 10 after the image transfer is removed and cleaned by the cleaning device 14, and the residual potential on the photoconductor 10 from which the residual toner has been removed is removed by a static elimination device (not shown). In preparation for the next image formation starting from the charging device 11.

  On the other hand, the sheet S after the image has been transferred is guided to the heat fixing device 24, passed between the heating roller 25 and the pressure roller 26, and conveyed to these rollers while applying heat and pressure to the toner. The image is fixed. Thereafter, the sheet S on which the image has been fixed is discharged onto the discharge stack unit 32 by the discharge roller 31 and stacked.

FIG. 3 is a schematic configuration diagram of the optical writing device 21.
The optical writing device 21 includes an LD unit 40, a collimating lens 52, an aperture 54, a cylindrical lens 53, a polygon scanner 50, a scanning lens (fθ lens) 43, a synchronizing mirror 62, a synchronizing lens 63, and the like. These are housed in an optical housing 80 as a housing. The optical housing 80 has a box shape with an open upper surface, and the upper surface is covered with a cover member 70 (see FIG. 7) to prevent dust from entering the optical writing device. The LD unit 40 is attached to the side surface of the optical housing 80. The collimating lens 52, the aperture 54, the cylindrical lens 53, the polygon scanner 50, the scanning lens (fθ lens) 43, the synchronization mirror 62, and the synchronization lens 63 are attached to a bottom surface portion 180 that is an attachment surface portion of the optical housing 80. The optical housing 80 is made of a thermoplastic resin containing glass fibers.

  The LD unit 40 includes a control substrate 42 to which a light source 41 composed of a semiconductor laser for irradiating the photoconductor 10 with a light beam L and a photo IC (not shown) are fixed.

  A polygon scanner 50 as a deflecting unit has a polygon mirror 49 which is a rotating polygon mirror having a regular polygonal column shape. The polygon scanner 50 is fastened by screws in the soundproof wall 55 of the optical housing 80. The polygon mirror 49 has reflecting mirrors on its six side surfaces. In the present embodiment, the polygon mirror 49 has a regular hexagonal prism shape and has six reflecting mirrors on the side surface. However, the present invention is not limited to this.

  The light beam L emitted from the light source 41 of the LD unit 40 is converted into a parallel light beam by the collimating lens 52. Thereafter, after being shaped by the aperture 54, the light passes through the cylindrical lens 53 and is condensed in the sub-scanning direction (direction corresponding to the direction of movement of the photosensitive member surface on the photosensitive member surface). Then, the light enters the polygon mirror 49. The light beam L incident on the polygon mirror 49 is deflected in the main scanning direction (direction corresponding to the axial direction on the surface of the photosensitive member) while being reflected by the reflecting mirror of the polygon mirror 49. Next, the light beam deflected in the main scanning direction at a constant angular velocity by the polygon mirror 49 passes through the soundproof glass 51 and enters the scanning lens 43. The scanning lens 43 converts the moving speed in the deflection direction of the light beam deflected in the main scanning direction at a constant angular velocity by the polygon mirror 49 to a constant velocity. After passing through the scanning lens 43, it is folded back by the synchronization mirror 62, condensed by the synchronization lens 63, and enters a photo IC (not shown) of the LD unit 40.

  When a photo IC (not shown) detects the light beam L, a synchronization signal is output. Then, the light beam L based on the image data emitted from the light source 41 in synchronization passes through the collimating lens 52, the aperture 54, the cylindrical lens 53, the polygon mirror 49, and the scanning lens 43 in the same manner as described above. The light beam L passing through the scanning lens 43 passes through a dustproof glass (not shown) provided so as to cover the opening formed on the side surface of the optical housing 80 and optically scans the surface of the photoconductor 10. .

FIG. 4 is a perspective view of the optical writing device 21 as viewed from below.
In the following description, the rotation axis direction of the polygon mirror 49 is set as the Z axis, the direction from the polygon mirror 49 toward the photoconductor 10 is set as the X axis, and the direction perpendicular to the Z-X plane is set as the Y axis.
The optical writing device 21 is a detachable unit that is detachably attached to the apparatus main body 100 of the copying machine. Specifically, in FIG. 1, the apparatus main body is configured to be detachable in a direction (Y-axis direction) orthogonal to the paper surface.

  As shown in FIG. 4, on the lower surface of the optical housing 80, there are three receiving portions 81, 82, 83 as positioned portions, and projecting portions 85, 86 as positioned portions.

  The first receiving portion 81 is provided on the lower surface of a first fixing portion 87 (described later) provided at the center portion in the X direction at the end portion on the near side in the mounting direction of the optical writing device 21. The second receiving portion 82 is a lower surface of the second fixing portion 88 provided at one end in the X direction (on the opposite side to the light beam emitting side of the optical writing device 21) at the end on the back side in the mounting direction of the optical writing device 21. Is provided. The third receiving portion 83 is provided on the lower surface of the third fixing portion 89 provided at one end in the X direction (on the light beam emitting side of the optical writing device 21) at the end on the back side in the mounting direction of the optical writing device 21. ing. Each of the receiving portions 81, 82, 83 has a quadrangular prism shape that protrudes slightly from the lower surface of each fixed portion, and the top surface has a highly accurate flatness. Further, the positions in the Z direction based on a certain portion of the optical writing device of each of the receiving portions 81, 82, 83 are the same position (the same height).

  A through hole 80 b is formed in the scanner mounting portion 182 that protrudes below the bottom surface portion 180 of the optical housing 80. The through hole 80b is fitted with a bearing portion 50a of a polygon motor (not shown) that rotates the polygon mirror 49, and the bottom surface of the bearing portion 50a is exposed. Further, a wall portion 181 that extends vertically downward is provided at the edge of the bottom surface portion 180, and the lower surface of the bottom surface portion 180 is surrounded by the wall portion 181.

FIG. 5 is a plan view showing a support plate 90 of the apparatus main body on which the optical writing device 21 is supported and positioned and fixed.
The support plate 90 has three positioning surfaces 91, 92, 93 and two positioning holes 95, 96. The first positioning surface 91 is provided at a location facing the first receiving portion 81 when the optical writing device 21 is mounted on the apparatus main body. The second positioning surface 92 is provided at a location facing the second receiving portion 82 when the optical writing device 21 is mounted on the apparatus main body. Further, the third positioning surface 93 is provided at a location facing the third receiving portion 83 when the optical writing device 21 is mounted on the apparatus main body. Each positioning surface 91, 92, 93 is provided so as to slightly protrude from the support plate 90, and each positioning surface 91, 92, 93 has a highly accurate flatness. Moreover, the height from the support plate 90 of each positioning surface 91,92,93 is the same.

  The first positioning hole 95 is provided at a position where the first protrusion 85 fits when the optical writing device 21 is mounted on the apparatus main body, and extends in the mounting direction (Y-axis direction) of the optical writing device 21. It has a hole shape. The second positioning hole 96 is provided at a position where the second protrusion 86 is fitted when the optical writing device 21 is mounted on the apparatus main body, and is approximately the same diameter (slightly larger) as the diameter of the second protrusion 86. It has a round hole shape with a diameter.

  When the optical writing device is mounted on the apparatus main body, the receiving portions 81, 82, 83 of the optical housing 80 abut on the corresponding positioning surfaces 91, 92, 93 of the support plate 90. The height of each receiving portion in the Z direction and the height of each positioning surface in the Z direction are aligned, and the flatness of the contact portion is also increased. Therefore, the optical housing 80 is positioned with respect to the apparatus main body in the Z-axis direction by the contact portions 81, 82, 83 coming into contact with the corresponding positioning surfaces 91, 92, 93. Further, the optical writing device 21 is positioned with respect to the apparatus main body about the X-axis direction and the Y-axis direction by the contact portions 81, 82, 83 coming into contact with the corresponding positioning surfaces 91, 92, 93, respectively. The

  Further, as the optical writing device 21 is attached, the first protrusion 85 is fitted into the first positioning hole 95. By fitting the first protrusion 85 in the positioning hole 95, the optical writing device 21 is positioned in the X-axis direction with respect to the apparatus main body.

  Further, when the optical writing device 21 is attached to the apparatus main body, the second protrusion 86 is fitted into the second positioning hole 96. As described above, in the second positioning hole 96, the diameter of the second protrusion 86 is substantially the same as the diameter of the second protrusion 86. Therefore, when the second protrusion 86 is fitted in the second positioning hole 96, the optical writing device 21 is positioned in the Y-axis direction with respect to the apparatus main body. Further, the protrusions 85 and 86 are fitted in the corresponding positioning holes 95 and 96, respectively, so that the optical writing device 21 is positioned around the Z-axis direction with respect to the apparatus main body.

  As shown in FIG. 5, the support plate 90 has a first leaf spring attachment portion 96 to which a leaf spring for fixing the first fixing portion 87 of the optical writing device 21 to the device main body is attached. Yes. Moreover, it has the 2nd leaf | plate spring attachment part 97 to which the leaf | plate spring for fixing the 2nd fixing | fixed part 88 to an apparatus main body is attached. The first leaf spring mounting portion 96 is provided so as to be adjacent to the back side of the first positioning surface 92 in the mounting direction of the optical writing device 21. The second leaf spring mounting portion 97 is provided so as to be adjacent to the back side of the second positioning surface 93 in the mounting direction of the optical writing device 21. A screw hole 91 a is provided at the center of the first positioning surface 91.

  Further, an opening 99 is formed at a location facing the scanner mounting portion 182 (see FIG. 4) of the optical housing 80 when the optical writing device 21 of the support plate 90 is mounted on the apparatus main body. The opening 99 has a lattice shape in which a plurality of round holes are regularly arranged in order to suppress a decrease in strength of the support plate 90 made of sheet metal. Further, the opening 99 is recessed by a drawing process to suppress a decrease in strength due to the provision of the opening. Since the support plate 90 is a member for positioning the optical writing device 21 with respect to the apparatus main body, the optical writing device 21 cannot be accurately positioned with respect to the apparatus main body if easily deformed. In the present embodiment, the opening 99 is formed in a lattice shape or is recessed by drawing to suppress the strength reduction, so that the deformation of the support plate 90 can be suppressed, and the optical writing device 21 can be suppressed. Can be accurately positioned on the main body.

FIG. 6 is an enlarged perspective view of the vicinity of the second positioning surface 92. (A) is a figure which shows a mode that the optical writer 21 is mounted | worn with the apparatus main body, (b) is a figure which shows a mode when the optical writer 21 is mounted | worn with the apparatus main body.
As shown in FIG. 6, a leaf spring 120 is attached to the first leaf spring attachment portion 96 of the support plate 90 shown in FIG. The tip of the leaf spring 120 is in contact with the second positioning surface 92.

  As shown in FIG. 6A, when the optical writing device 21 is attached to the apparatus main body, the second fixing portion 88 of the optical housing 80 enters between the leaf spring 120 and the second positioning surface 92. . Thereby, as shown in FIG. 6B, the second fixing portion 88 is pressed and fixed to the second positioning surface 92 side by the leaf spring 120.

  Similarly to the second fixing portion 88, the third fixing portion 89 of the optical housing 80 is pressed and fixed to the third positioning surface 93 side by the leaf spring.

FIG. 7 is a perspective view showing a state in which the optical writing device 21 is positioned and fixed to the support plate 90.
As shown in FIG. 7, the first fixing portion 87 of the optical writing device 21 is provided with a screw through hole (not shown). When the optical writing device 21 is positioned on the support plate 90, the screw 91b is inserted into a screw through hole (not shown), and the screw 91b is screwed into the screw hole 91a shown in FIG. The part 87 is fixed to the support plate 90.
Further, as shown in FIG. 7, both ends of the support plate 90 in the X-axis direction are bent perpendicular to the Z-axis direction, and side portions 98a and 98b are formed. One side surface 98b is formed with a beam passage opening 198b for allowing the light beam emitted from the optical writing device 21 to pass therethrough. The other side surface 98a is provided with three duct fixing portions 198a to which the duct 111 is fixed.

FIG. 8 is a cross-sectional perspective view around the optical writing device 21.
As shown in FIG. 8, a duct 111 is provided so as to cover the optical writing device 21 from above, which is the cover member side of the optical writing device 21. The duct 111 has a shape such that the cross-sectional area decreases as it goes upward, and the upper side is connected to the exhaust fan 112 as shown in FIG.

  A waste toner bottle storage portion 135 that stores the waste toner bottle 35 is formed below the optical writing device 21. The waste toner bottle storage portion 135 is formed so as to be surrounded by the support plate 90 and the plurality of face plates 110a, 110b, 110c, and 110d. With this configuration, the optical writing device 21 and the waste toner bottle 35 can be partitioned by the support plate 90. By partitioning with the support plate 90, it is possible to prevent the user from touching the optical writing device 21 from the waste toner bottle storage portion 135 when the waste toner bottle 35 is taken out from the apparatus main body.

  The waste toner bottle storage unit 135 and the space in which the optical writing device 21 is disposed communicate with each other through the opening 99 of the support plate 90. The waste toner bottle storage portion 135 is surrounded by a support plate 90, a plurality of face plates 110a, 110b, 110c, and 110d, face plates provided on the back side and the near side (not shown), except for the opening 99. It is a substantially shielded space that substantially shields sound. The process cartridge 1 is disposed above the face plate 110d. Further, a silencer 351 that is a silencer for eliminating the sound generated when the polygon scanner is driven is formed at a position facing the opening 99 of the waste toner bottle 35.

FIG. 9 is an enlarged cross-sectional perspective view around the polygon scanner 50 of the optical writing device 21.
As shown in FIG. 9, the silencer 351 is formed in a portion that is recessed by one step from the outer peripheral surface of the waste toner bottle 35, and has a serrated uneven shape.

FIG. 10 is a diagram illustrating the air flow around the optical writing device 21 and the sound propagation when the polygon scanner 50 is driven. Solid arrows in the figure indicate air flow, and chain lines in the figure indicate sound propagation.
When a latent image is formed on the surface of the photoconductor 10, the polygon mirror 49 is rotated at a high speed of 3 to 40,000 rpm, and the polygon motor bearing 50a generates heat. When the polygon motor is driven, the electronic control components on the circuit board 50b also generate heat. Since the optical writing device 21 is hermetically sealed by the optical housing 80 and the cover member 70, the heat generated in these heat generating portions (bearing portion and electronic control component) is scattered inside the optical writing device, and the inside. Becomes hot. When the temperature inside the optical writing device becomes high, the bottom surface portion 180 of the optical housing 80 is thermally expanded, and the collimating lens 52, the aperture 54, the cylindrical lens 53, the polygon scanner 50, the scanning lens (fθ) fixed to the bottom surface portion 180. Lens) 43, synchronization mirror 62, synchronization lens 63, and other optical system components change their posture. In addition, the optical system component may be thermally deformed. If the optical system component is thermally deformed or its posture is changed, there is a possibility that the writing light cannot be imaged on the surface of the photoreceptor. The temperature of the scanner mounting portion 182 to which the bearing portion 50a, which is a heat generation source, is fitted and fixed or the circuit board 50b is fixed is particularly high.

  Further, the polygon scanner 50 generates sound during driving, such as wind noise of the polygon mirror 49 that rotates at high speed. Since the inside of the optical writing device 21 is a space shielded by the optical housing 80 and the cover member 70, the sound of the polygon scanner leaking from the side surface of the cover member 70 or the optical housing 80 is slight. However, in the present embodiment, the bearing portion 50a of the polygon scanner is exposed outside the apparatus, and the sound of the polygon scanner 50 may be emitted from the exposed bearing portion 50a. Further, the polygon scanner 50 vibrates by rotating at a high speed, and the vibration propagates to the scanner attachment unit 182 to which the polygon scanner is fixed, and the scanner attachment unit 182 vibrates. As the scanner mounting portion 182 vibrates, so-called solid-propagating sound is also generated in which the scanner mounting portion 182 functions like a speaker to generate sound.

  The image forming apparatus described in Patent Document 1 is provided with an opening for taking air into the duct above the polygon scanner. Since the opening is above the polygon scanner, most of the air taken into the duct from the opening hits the polygon mirror facing part of the cover member attached to the top of the optical housing. And flow along the cover member. As a result, the flow rate of air flowing from the side surface of the optical housing between the support plate and the bottom surface portion is small. The bearing part of the polygon motor, which is a heat generation source, and the electronic control parts on the control board are on the bottom surface side of the optical housing, and the heat is propagated to the scanner mounting portion on the bottom surface portion so that the temperature becomes the highest. In Patent Document 1, since the flow rate of the air flowing into the scanner mounting portion which is the mounting surface portion that is the highest temperature is small, the optical writing device cannot be sufficiently cooled.

  On the other hand, in the present embodiment, an opening 99 is formed at a location facing the scanner mounting portion 182 of the support plate 90. When the air inside the duct 111 is exhausted by the exhaust fan 112 and the inside of the duct 111 becomes negative pressure, as shown by the solid line arrow in the figure, the duct 111 is formed from the gap between the support plate 90 and the duct 111 or the beam passage port 198b. Air flows into. Air also flows from the opening 99 toward the duct 111. The air flowing from the opening 99 first hits the scanner mounting portion 182 of the optical housing 80 that is the highest temperature in the optical writing device 21 and the bearing portion 50 a of the polygon scanner exposed from the optical housing 80. As a result, air having a low temperature can be applied to the scanner mounting portion 182 and the bearing portion 50 a that are the highest temperature in the optical writing device 21. As a result, the heat of the scanner mounting part 182 and the bearing part 50a can be taken away favorably, and the temperature rise of the scanner mounting part 182 and the bearing part 50a can be suppressed satisfactorily. The air whose temperature has risen due to the removal of heat from the scanner mounting portion 182 and the bearing portion 50a flows into the duct 111, and new low-temperature air flows from the opening 99 into the scanner mounting portion 182 and the bearing portion 50a. Thereby, heat does not stay between the scanner attachment part 182 and the support plate 90, and the temperature rise of the scanner attachment part 182 and the bearing part 50a can be suppressed favorably. In the present embodiment, the duct 111 is disposed above the optical writing device 21. Therefore, the air whose temperature has risen due to heat removal flows toward the duct 111 by the rising airflow. Thereby, it is possible to further suppress the heat from staying between the scanner mounting portion 182 and the support plate 90.

  The opening area of the opening 99 is larger than the gap between the support plate 90 and the duct 111 and the beam passage opening 198b. For this reason, much air flows in from the opening part 99, and the scanner attaching part 182 and the bearing part 50a can be air-cooled efficiently.

  As described above, by providing the opening 99 at a position facing the scanner mounting portion 182 of the support plate 90, the bottom surface portion 180 of the optical housing 90 can be satisfactorily cooled, and thermal expansion of the bottom surface portion 180 can be suppressed. . As a result, the postures of optical system components such as the collimating lens 52, the aperture 54, the cylindrical lens 53, the polygon scanner 50, the scanning lens (fθ lens) 43, the synchronizing mirror 62, and the synchronizing lens 63 that are fixed to the bottom surface portion 180 are changed. Can be suppressed. Moreover, it can suppress that the inside of an optical housing becomes high temperature, and can suppress that an optical system component heat-deforms.

  Further, the sound emitted from the bearing portion 50a exposed from the optical writing device 21 and the scanner mounting portion 182 leaks from the opening 99 as indicated by the chain line arrow in the figure. Most of the sound leaking from the opening 99 hits the slope of the mountain of the muffler 351 provided in the waste toner bottle 35 facing the opening 99. The sound that hits the slope of the mountain of the silencer 351 is reflected and hits the slope of the adjacent mountain. In this way, by applying a sound to the slope of the mountain a plurality of times, the sound can be attenuated and a silencing effect can be obtained.

  Further, a part of the sound leaking from the opening 99 does not hit the silencer 351 and is reflected in the waste toner bottle storage unit 135. In the present embodiment, since the waste toner bottle storage unit 135 is a substantially shielded space, it is possible to suppress leakage of sound from the waste toner bottle storage unit 135 to the outside of the apparatus. Note that the term “substantially shielded space” as used herein refers to a space surrounded by walls with at least the top, bottom, left, right, front, and back, and there is a slight gap such as an opening in the wall, which may cause sound leakage. Refers to a space almost shielded by an enclosed wall. Even if sound leaks from an opening or the like provided in a wall (face plate) that surrounds the waste toner bottle storage unit 135, the path through which the sound reaches the exhaust port 113 bypasses the support plate 90 and the duct 111. It becomes a route. The path is longer than the path that reflects the support plate 90 and moves through the duct 111 and leaks from the exhaust port 113. As a result, even if sound leaks from the opening provided on the wall (face plate) surrounding the waste toner bottle storage unit 135 from the exhaust port 113, the sound is sufficiently attenuated before leaking from the exhaust port 113. Therefore, it is possible to suppress the noise that is annoying for the user.

  Also, as shown in FIG. 10, a part of the sound emitted from the bearing portion 50 a exposed from the optical writing device 21 and the scanner mounting portion 182 does not pass through the opening 99 and hits the support plate 90. However, as shown in FIG. 10, the sound that hits the support plate 90 is also shielded by the wall portion 181 that extends downward from the edge of the bottom surface portion 180 of the optical housing 80, thereby suppressing the sound from leaking to the duct 111 side. be able to. Thereby, it is possible to suppress the sound emitted from the bearing portion 50a and the scanner mounting portion 182 from leaking from the exhaust port 113.

  Thus, in the present embodiment, the optical writing device 21 can be cooled satisfactorily by providing the opening 99 at the portion of the support plate 90 facing the scanner mounting portion 182, and the exhaust port 113. It is possible to suppress noise that leaks from the air.

FIG. 11 is a diagram illustrating a modification of the muffler 351.
In this modification, a sound absorbing member 352 is attached to the muffler 351. By affixing the sound absorbing member 352, the sound hitting the mountain of the sound deadening portion 351 is absorbed by the sound absorbing member 352, and the sound deadening effect by the sound deadening portion 351 can be enhanced. Further, the surface of the waste toner bottle 35 facing the opening 99 may be a flat surface, and the sound absorbing member 352 may be attached thereto. Even in this case, most of the sound emitted from the scanner mounting portion 182 and the bearing portion 50 a that have passed through the opening 99 can be absorbed by the sound absorbing member 352. The sound absorbing member 352 may be attached to the support plate 90, the duct 111, or the like. Furthermore, the sound absorbing member 352 may be attached to the wall surface constituting the waste toner bottle storage unit 135. Thereby, the soundproofing effect can be further enhanced.

FIG. 12 is a view showing a modification in which the lower surface of the process cartridge is used as a wall that shields the waste toner bottle storage unit 135.
As shown in FIG. 12, in this modification, the face plate 110 d is eliminated, and the lower surface of the process cartridge that is the waste toner bottle facing surface is used as a wall that shields the waste toner bottle storage portion 135. As shown in FIG. 8, the surface provided with the face plate 110d can completely shield the upper surface of the waste toner bottle storage unit 135, and therefore has higher sound insulation. However, as shown in FIG. 12, the lower surface of the process cartridge 1 is close to the waste toner bottle storage part 135, and the open gaps D1 and D2 are also slight. Therefore, even on the lower surface of the process cartridge, it is possible to sufficiently shield the sound of the scanner mounting portion 182 and the bearing portion 50a that have entered the waste toner bottle storage portion from the opening 99. Even if sound leaks from the gap D1 or the gap D2, the path to the exhaust port 113 is longer than the path that reflects the support plate 90 and passes through the duct 111 to the exhaust port 113. Therefore, when the sound is sufficiently attenuated before reaching the exhaust port 113 and leaks from the exhaust port 113 to the outside of the machine, the sound can be at a level that is not harsh to the user, and the noise of the apparatus can be suppressed well.

What has been described above is an example, and the present invention has a specific effect for each of the following aspects.
(Aspect 1)
A latent image carrier such as the photosensitive member 20, a light source 41 that emits light, a deflecting unit such as a polygon scanner 50 that deflects and scans the light emitted from the light source 41, and an optical housing 80 that houses the deflecting unit. An optical writing means such as an optical writing device 21 that has a casing and irradiates the latent image carrier with a light beam that has been deflected and scanned by the deflection means, and writes the latent image on the latent image carrier; Opposite the outer peripheral surface of a mounting portion such as a scanner mounting portion 182 to which the deflecting means of the housing is mounted with a predetermined gap, the support plate 90 that supports the housing and the optical writing device sandwiched above An exhaust port 113 provided on the side opposite to the side on which the support plate 90 is disposed, and the casing from the side opposite to the side on which the support plate 90 is disposed are disposed so as to cover the casing. Flow air toward the exhaust port 113 Duct 111 and airflow generating means such as an exhaust fan 112 that generates an airflow that flows to the exhaust port 113 after flowing the air around the casing along the outer peripheral surface of the casing. In the image forming apparatus, an opening 99 is provided at a location facing the outer peripheral surface of the mounting portion of the support plate 90.
According to (Aspect 1), the sound at the time of driving the deflecting means such as the polygon scanner 50 emitted from the attachment portion such as the scanner attachment portion 182 can be escaped from the opening 99. As a result, the sound generated from the attachment portion advances through the gap between the support plate 90 and the attachment portion while being reflected by the respective surfaces of the support plate 90 and the attachment portion, and then the inside of the duct 111 is directed to the exhaust port 113. And leaking from the exhaust port 113 can be suppressed.
If the space on the opposite side of the writing means installation side with respect to the support plate 90 (in this embodiment, the waste toner bottle storage portion 135) is a shielded space, the sound escaping from the opening 99 will enter the shielded space. The sound does not leak out from the exhaust port 113, and the noise of the apparatus can be suppressed. Further, even if the space opposite to the writing means installation side across the support plate 90 is not a shielded space but communicates with the exhaust port 113, at least the sound that escapes from the opening 99 is at least the support plate 90 and the duct. Bypassing 111, the optical writing means is sandwiched, and the exhaust port 113 is located on the side opposite to the support plate side. Therefore, it can be made longer than the conventional route that moves in the duct 111 and goes to the exhaust port 113. As the path becomes longer, the sound is attenuated. Therefore, even if the sound of the deflecting means leaks from the exhaust port 113 in the end, the sound travels through the duct 111 and leaks from the exhaust port 113. Sound can be reduced. Therefore, even if the space opposite to the writing means installation side across the support plate 90 is not a shielding space but communicates with the exhaust port 113, the noise of the apparatus is reduced as compared with the configuration described in Patent Document 1. can do.

(Aspect 2)
In (Aspect 1), the space opposite to the space on the optical writing means installation side such as the optical writing device 21 with respect to the support plate 90 is a substantially shielded space that is substantially shielded except for the opening 99. did.
According to this, as described in the embodiment, the sound from the attachment portion such as the scanner attachment portion 182 that has passed through the opening 99 and the bearing portion 50a is shielded by the substantially shielded space, and the machine from the exhaust port 113 It is possible to suppress leakage to the outside. Thereby, the noise of an apparatus can be suppressed.

(Aspect 3)
In (Aspect 1) or (Aspect 2), the opening 99 of the member disposed in the space opposite to the space on the optical writing means installation side such as the optical writing device 21 with respect to the support plate 90 as a reference. Silencer means such as a silencer 351 is provided in a portion opposite to.
According to this, as described in the embodiment, the sound from the mounting surface portion such as the scanner mounting portion 182 and the bearing portion 50a that has passed through the opening 99 hits the sound deadening means and is muted. Thereby, the noise of an apparatus can be suppressed.

(Aspect 4)
In (Aspect 3), the muffler has an uneven portion.
According to this, as described in the embodiment, the sound from the mounting surface portion such as the scanner mounting portion 182 that has passed through the opening 99 or the sound from the bearing portion 50a hits the convex slope more than once, so that the sound is generated. It is attenuated and can be muted.

(Aspect 5)
In (Aspect 3) or (Aspect 4), the silencer such as the silencer 351 includes a sound absorbing member 352.
According to this, the sound from the attachment surface portion such as the scanner attachment portion 182 and the bearing portion 50a that has passed through the opening 99 can be absorbed by the sound absorbing member 352 and muffled.

(Aspect 6)
In (Aspect 3) to (Aspect 5), the member disposed in the space opposite to the space on the optical writing means installation side with respect to the support plate 90 is a waste toner bottle.
According to this, the number of parts can be reduced and the cost of the apparatus can be reduced as compared with a case where a member opposed to the opening 99 is provided separately from the waste toner bottle, and a silencer is provided for it. it can.

1: Process cartridge 10: Photoconductor 21: Optical writing device 35: Waste toner bottle 41: Light source 49: Polygon mirror 50: Polygon scanner 50a: Bearing portion 50b: Circuit board 70: Cover member 80: Optical housing 80b: Through hole 90: Support plate 99: Opening part 111: Duct 112: Exhaust fan 113: Exhaust port 135: Waste toner bottle storage part 180: Bottom part 181: Wall part 182: Scanner attachment part 351: Silencer part 352: Sound absorbing member

Japanese Patent No. 4655639

Claims (6)

A latent image carrier;
A light source for irradiating a light beam, a deflecting unit for deflecting and scanning the light beam emitted from the light source, and a housing for housing the deflecting unit therein, and the latent image carrier for the light beam deflected and scanned by the deflecting unit An optical writing means for irradiating on and writing a latent image on the latent image carrier;
A support plate for supporting the casing, facing the outer peripheral surface of the mounting portion to which the deflecting means of the casing is mounted with a predetermined gap;
An exhaust port provided on the side opposite to the side on which the support plate is disposed across the optical writing means;
A duct for covering the casing from the side opposite to the side on which the support plate is disposed, and a duct for flowing air around the casing toward the exhaust port;
In an image forming apparatus comprising: an airflow generation unit configured to generate an airflow that flows to the exhaust port after flowing the air around the housing along the outer peripheral surface of the housing;
An image forming apparatus, wherein an opening is provided at a location facing the outer peripheral surface of the mounting portion of the support plate. The image forming apparatus according to claim 1.
An image forming apparatus, wherein a space opposite to the space on the optical writing means installation side with the support plate interposed therebetween is a substantially shielded space except for the opening. The image forming apparatus according to claim 1, wherein
An image forming apparatus, wherein a silencer is provided at a portion facing the opening of a member disposed in a space opposite to the space on the optical writing means installation side with the support plate interposed therebetween. The image forming apparatus according to claim 3.
An image forming apparatus, wherein the muffling means has a concavo-convex shape portion. The image forming apparatus according to claim 3 or 4, wherein:
The muffling unit includes a sound absorbing member. The image forming apparatus according to claim 3, wherein:
An image forming apparatus, wherein a member disposed in a space opposite to the space on the optical writing means installation side with respect to the support plate is a waste toner bottle.

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